I started it a few months ago, after I turned 51. I thought I would fail my certification test, for my new advanced position in psychological counseling, as it required reviewing materials I had not studied, since the 1970s , as well as some new theories that I do not particularly believe in-- but needed to know.
I passed the test in flying colors and have noticed that I really enjoy reading voraciously. My job performance has increased significantly, as well as my hobbies. I also recommend Paul Scheele's book on Natural Brilliance, which shows how to apply PR principles in other areas of life.